Technical Note on Simplified Free Gingival Graft Using Tack Fixation (sFGG)

Free gingival graft (FGG) is the gold standard procedure for the reliable augmentation of lost keratinized mucosa (KM) around dental implants. This conventional surgical approach has its drawbacks, including limitations in manipulation, the requirement for suturing, postoperative discomfort, and pain. This case report aimed to evaluate the efficacy of a simplified free gingival graft (sFGG) in addressing the issue of inadequate keratinized mucosa around dental implants. Fixation tacks were used to perform the sFGG procedure. Initially, a partial-thickness flap was created and apically repositioned. The gingival graft was harvested from the palate with a narrow profile and securely affixed to the recipient site using 5 mm long fixation tacks. Significant gains in keratinized mucosa were achieved and successfully maintained within 1 year. Consequently, the sFGG technique emerges as a simple and reliable treatment approach for managing inadequate keratinized mucosa around dental implants.

Volumetric evaluation of effects of platelet-rich fibrin and concentrated growth factor on early bone healing after endodontic microsurgery: a randomized controlled trial

BACKGROUND

This randomized controlled clinical trial compared the effects of platelet-rich fibrin (PRF) and concentrated growth factor (CGF) on early bone healing after endodontic microsurgery.

METHODS

Eighteen patients with an isolated periapical lesion < 10 mm in the maxillary anterior region were randomly assigned to three groups: control, PRF, or CGF. Endodontic microsurgery was performed and PRF or CGF membranes were placed over the bone defects in the experimental groups. The volume of the bone defect at postoperative one week, three months, and six months was evaluated using cone-beam computed tomography and Mimics software. The results were statistically analyzed using the Kruskal-Wallis test and post-hoc Mann-Whitney U test with Bonferroni correction.

RESULTS

At the three-month follow-up, the PRF and CGF groups showed significantly greater bone healing compared with the control group (p > 0.05). However, no significant difference was observed between the PRF and CGF groups. At the six-month follow-up, no significant differences were observed between the groups.

CONCLUSIONS

These results suggested that PRF and CGF promote early bone healing after endodontic microsurgery.

25-Hydroxycholesterol induces odontoclastic differentiation through RANK-RANKL upregulation and NF-κB activation in odontoblast-like MDPC-23 cells: An in vitro study

AIM

The physiological effects and cellular mechanism of 25-hydroxycholesterol (25-HC), which is an oxysterol synthesized from cholesterol by cholesterol-25-hydroxylase (CH25H) expressed under inflammatory conditions, are still largely unknown during odontoclastogenesis. This study aimed to evaluate 25-HC-induced odontoclastogenesis and its cellular mechanisms in odontoblast-like MDPC-23 cells.

METHODOLOGY

To investigate 25-HC-induced odontoclastogenesis of MDPC-23 cells and its cellular mechanism, haemotoxylin and eosin staining, tartrate-resistant acid phosphatase (TRAP) staining, dentine resorption assay, zymography, reactive oxygen species (ROS) detection, immunocytochemistry, and nuclear translocation were performed. The experimental values are presented as mean ± standard deviation and were compared using analysis of variance, followed by post hoc multiple comparisons (Tukey's test) using SPSS software version 22 (IBM Corp.). A p-value <.05 was considered statistically significant.

RESULTS

Lipopolysaccharide or receptor activator of nuclear factor-κB ligand (RANKL) induced the synthesis of 25-HC via the expression of CH25H in MDPC-23 cells (p < .01). Multinucleated giant cells with morphological characteristics and TRAP activity of the odontoclast were increased by 25-HC in MDPC-23 cells (p < .01). Moreover, 25-HC increased dentine resorption through the expression and activity of matrix metalloproteinases in MDPC-23 cells. It not only increased the expression of odontoclastogenic biomarkers but also translocated cytosolic nuclear factor-κB (NF-κB) to the nucleus in MDPC-23 cells. Additionally, 25-HC not only increased the production of ROS (p < .01), expression of inflammatory mediators (p < .01), pro-inflammatory cytokines, receptor activator of NF-κB (RANK), and RANKL but also suppressed the expression of osteoprotegerin (OPG) in MDPC-23 cells. In contrast, CDDO-Me, a chemical NF-κB inhibitor, decreased TRAP activity (p < .01) and downregulated the expression of the odontoclastogenic biomarkers, including RANK and RANKL, in MDPC-23 cells.

CONCLUSION

25-HC induced odontoclastogenesis by modulating the RANK-RANKL-OPG axis via NF-κB activation in MDPC-23 cells. Therefore, these findings provide that 25-HC derived from cholesterol metabolism may be involved in the pathophysiological etiological factors of internal tooth resorption.

GPR183 Regulates 7α,25-Dihydroxycholesterol-Induced Oxiapoptophagy in L929 Mouse Fibroblast Cell

7α,25-dihydroxycholesterol (7α,25-DHC) is an oxysterol synthesized from 25-hydroxycholesterol by cytochrome P450 family 7 subfamily B member 1 (CYP7B1) and is a monooxygenase (oxysterol-7α-hydroxylase) expressed under inflammatory conditions in various cell types. In this study, we verified that 7α,25-DHC-induced oxiapoptophagy is mediated by apoptosis, oxidative stress, and autophagy in L929 mouse fibroblasts. MTT assays and live/dead cell staining revealed that cytotoxicity was increased by 7α,25-DHC in L929 cells. Consequentially, cells with condensed chromatin and altered morphology were enhanced in L929 cells incubated with 7α,25-DHC for 48 h. Furthermore, apoptotic population was increased by 7α,25-DHC exposure through the cascade activation of caspase-9, caspase-3, and poly (ADP-ribose) polymerase in the intrinsic pathway of apoptosis in these cells. 7α,25-DHC upregulated reactive oxygen species (ROS) in L929 cells. Expression of autophagy biomarkers, including beclin-1 and LC3, was significantly increased by 7α,25-DHC treatment in L929 cells. 7α,25-DHC inhibits the phosphorylation of Akt associated with autophagy and increases p53 expression in L929 cells. In addition, inhibition of G-protein-coupled receptor 183 (GPR183), a receptor of 7α,25-DHC, using GPR183 specific antagonist NIBR189 suppressed 7α,25-DHC-induced apoptosis, ROS production, and autophagy in L929 cells. Collectively, GPR183 regulates 7α,25-DHC-induced oxiapoptophagy in L929 cells.

25-Hydroxycholesterol-Induced Oxiapoptophagy in L929 Mouse Fibroblast Cell Line

25-hydroxycholesterol (25-HC) is an oxysterol synthesized from cholesterol by cholesterol-25-hydroxylase during cholesterol metabolism. The aim of this study was to verify whether 25-HC induces oxiapoptophagy in fibroblasts. 25-HC not only decreased the survival of L929 cells, but also increased the number of cells with condensed chromatin and altered morphology. Fluorescence-activated cell sorting results showed that there was a dose-dependent increase in the apoptotic populations of L929 cells upon treatment with 25-HC. 25-HC-induced apoptotic cell death was mediated by the death receptor-dependent extrinsic and mitochondria-dependent intrinsic apoptosis pathway, through the cascade activation of caspases including caspase-8, -9, and -3 in L929 cells. There was an increase in the levels of reactive oxygen species and inflammatory mediators such as inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E2 in L929 cells treated with 25-HC. Moreover, 25-HC caused an increase in the expression of beclin-1 and microtubule-associated protein 1A/1B-light chain 3, an autophagy biomarker, in L929 cells. There was a significant decrease in the phosphorylation of protein kinase B (Akt) in L929 cells treated with 25-HC. Taken together, 25-HC induced oxiapoptophagy through the modulation of Akt and p53 cellular signaling pathways in L929 cells.

Comparison of Various Time-Related Modifications of Ultraviolet Photofunctionalization on SLA-Treated Titanium Surfaces

PURPOSE

The purpose of this study was to compare changes in the physicochemical and biologic characteristics of titanium surfaces through short-term re-hydrophobization for 24 hours and ultraviolet (UV) re-irradiation for 24 hours.

MATERIALS AND METHODS

Photofunctionalization was performed with four 15-W bactericidal lamps at an intensity of 5.0 mW/cm² (wavelength = 254 ± 20 nm) on sandblasted, large-grit, acid-etched (SLA)-treated titanium surfaces, which were stored in a sterilized sealed container for 8 weeks to allow enough biologic aging. The duration of the UV irradiation was as follows: irradiation group-UV irradiated for 24 hours; re-hydrophobization group-UV irradiated for 24 hours and then stored in an ambient sterilized medium; and re-irradiation group-UV irradiated for 24 hours followed by storing for 24 hours in an ambient sterilized medium and then UV re-irradiated for 24 hours. The surface characteristics were evaluated with field emission scanning electron microscopy, x-ray photoelectron spectroscopy (XPS), and water contact angle. Cell viability and morphology were measured using fluorescence staining. Alkaline phosphatase (ALP) assay and alizarin red S staining were performed to evaluate the differentiation of osteogenic cells and the mineralization capability.

RESULTS

Macroroughness and superimposed microroughness were observed on the disk surfaces in all groups as typically seen on SLA surfaces. The water contact angles were measured to be 1.85, 1.48, and 1.18 degrees for the irradiation group, re-hydrophobization group, and re-irradiation group, respectively, indicating superhydrophilicity. There was no difference in the surface elemental ratio or the spectra of XPS, cell viability, or ALP activity. Although the re-irradiation group had the highest total amount of calcium deposition, there was no statistical significance.

CONCLUSION

Within the limitations of the study, improved superhydrophilicity and bioactivity after UV irradiation were maintained during short-term re-hydrophobization and repeated re-irradiation without changing the topography of SLA titanium surfaces.

Demethoxycurcumin induces apoptosis via inhibition of NF-κB pathway in FaDu human head and neck squamous cell carcinoma

Background

Demethoxycurcumin (DMC) is a curcumin analog with antitumor properties. However, its effects have not been investigated in human head and neck squamous cell carcinoma (HNSCC). The aim of the present study was to verify the antitumor effect and cellular signaling pathways of DMC in FaDu HNSCC cells.

Methods

3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cell Live/Dead staining, hematoxylin and eosin staining, DAPI staining, FACS, western blotting, caspase-3 activity assay, and nuclear translocation were performed to verify apoptosis and the cellular signaling pathway of DMC in FaDu cells.

Results

DMC increased FaDu cell death, with cells presenting altered morphology and condensed nuclei. DMC increased significantly the apoptotic population of FaDu cells. Sequentially, DMC increased the expression of cleaved caspase-3 and PARP through the up-regulation of pro-apoptotic factors such as FasL, cleaved caspase-8, Bax, Bad, and cleaved caspase-9 and the suppression of anti-apoptotic factors including Bcl-xL and Bcl-2 in FaDu cells. Furthermore, DMC not only suppressed the phosphorylation of NF-κB, but also inhibited the translocation of NF-κB from cytosol to nucleus of FaDu cells.

Conclusions

Present study demonstrates that DMC-induced cell death is mediated caspase-dependently by death receptor-mediated extrinsic and mitochondria-dependent intrinsic apoptosis through the inhibition of NF-κB translocation from the cytosol to the nucleus of FaDu cells. DMC is a curcuminoid with antitumor properties that modulates the NF-κB cellular signaling pathway in FaDu cells. Taken together, this study suggests that DMC has a considerable chemotherapeutic potential for HNSCC.

Oxysterol 25-hydroxycholesterol as a metabolic pathophysiological factors of osteoarthritis induces apoptosis in primary rat chondrocytes

The aim of the present study was to investigate the pathophysiological etiology of osteoarthritis that is mediated by the apoptosis of chondrocytes exposed to 25-hydroxycholesterol (25-HC), an oxysterol synthesized by the expression of cholesterol-25-hydroxylase (CH25H) under inflammatory conditions. Interleukin-1β induced the apoptosis of chondrocytes in a dose- dependent manner. Furthermore, the production of 25-HC increased in the chondrocytes treated with interleukin-1β through the expression of CH25H. 25-HC decreased the viability of chondrocytes. Chondrocytes with condensed nucleus and apoptotic populations increased by 25-HC. Moreover, the activity and expression of caspase-3 were increased by the death ligand-mediated extrinsic and mitochondria-dependent intrinsic apoptotic pathways in the chondrocytes treated with 25-HC. Finally, 25-HC induced not only caspase-dependent apoptosis, but also induced proteoglycan loss in articular cartilage ex vivo cultured rat knee joints. These data indicate that 25-HC may act as a metabolic pathophysiological factor in osteoarthritis that is mediated by progressive chondrocyte death in the articular cartilage with inflammatory condition.

25-Hydroxycholesterol Induces Death Receptor-mediated Extrinsic and Mitochondria-dependent Intrinsic Apoptosis in Head and Neck Squamous Cell Carcinoma Cells

BACKGROUND/AIM

Oxysterol plays important physiological roles in diverse biological processes including apoptosis. However, the mechanisms underlying oxysterol-induced apoptosis remain unknown. 25-hydroxycholesterol (25-HC) is an oxysterol synthesized by cholesterol 25-hydroxylase from cholesterol during sterol metabolism. The aim of present study was to investigate 25-HC-induced apoptosis and associated signalling pathways in FaDu cells, which is originated form human head and neck squamous cell carcinoma cells.

MATERIALS AND METHODS

25-HC-induced apoptosis was investigated by cell cytotoxicity assay using MTT, cell viability assay using cell LIVE/DEAD cell viability assay, haematoxylin & eosin staining, nuclear staining, fluorescence-activated cell sorting, western blotting using specific antibodies associated with extrinsic and intrinsic apoptosis pathways, and caspase-3/-7 activity assay in FaDu cells.

RESULTS

25-HC dose-dependently decreased the viability of FaDu cells and up-regulated apoptotic events, such as alteration in morphology, and nuclear condensation. Flow cytometric analysis showed an increase in apoptotic population upon 25-HC treatment, suggesting that 25-HC induces apoptosis in FaDu cells. Moreover, 25-HC-induced apoptosis in FaDu cells was dependent on the activation of caspases by Fas antigen ligand-triggered death receptor-mediated extrinsic pathway and mitochondria-dependent intrinsic pathway via mitogen activated protein kinases.

CONCLUSION

Cholesterol-derived oxysterol, 25-HC has potential anti-cancer function in FaDu cells and may have potential properties for the discovery of anti-cancer agents.

Formononetin induces apoptotic cell death through the suppression of mitogen‑activated protein kinase and nuclear factor‑κB phosphorylation in FaDu human head and neck squamous cell carcinoma cells

Formononetin, a phytoestrogen extracted from various herbal plants, has been investigated as an anticancer agent against diverse types of cancer. The aim of the present study was to investigate the induction of apoptotic cell death by formononetin in the FaDu pharyngeal squamous cell carcinoma cell line. Formononetin significantly increased FaDu cell death, with an estimated IC50 value of 50 µM; however, it did not affect the viability of normal L929 mouse fibroblasts used as normal control at 5‑25 µM. Typical characteristics of apoptosis, such as morphological alterations, chromatin condensation, DNA fragmentation and the size of the apoptotic cell population, were increased in FaDu cells treated with formononetin for 24 h. Furthermore, formononetin‑induced FaDu cell death involved the death receptor‑mediated extrinsic and the mitochondria‑dependent intrinsic apoptotic pathways by activating the caspase cascade. The chemotherapeutic effects of formononetin were mediated by the suppression of mitogen‑activated protein kinases, including extracellular signal‑regulated kinase 1/2 and p38, and nuclear factor‑κB phosphorylation in FaDu cells. Finally, the oral administration of formononetin decelerated tumor growth through the expression of cleaved caspase‑3 in a FaDu cell xenograft animal model. Taken together, these findings indicate that formononetin holds promise as a chemotherapeutic agent and may be of value in the treatment of human head and neck squamous cell carcinoma.

Recovery of renal function in patients with lupus nephritis and reduced renal function: the beneficial effect of hydroxychloroquine

Background

Reduced renal function is associated with worse renal outcome in patients with lupus nephritis (LN). However, there is insufficient knowledge regarding renal function recovery in patients with LN with reduced baseline renal function. Therefore, the present study aimed to investigate renal function recovery and related factors in patients with reduced baseline renal function.

Methods

The present retrospective longitudinal cohort study included patients with LN and reduced renal function. Reduced renal function was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2. Recovery of renal function was determined by an eGFR of >60 mL/min/1.73 m2 at six months after baseline, and factors associated with it were evaluated using logistic regression analysis.

Results

We included 90 patients with LN, with a mean eGFR value of 37.2 ± 13.9 mL/min/1.73 m2. Forty-six (51.1%) patients recovered their renal function after six months. On multivariate analysis, hydroxychloroquine use (odds ratio (OR) = 3.891, 95% confidence interval (CI) 1.196–12.653, p = 0.024), prolonged LN (OR = 0.926, 95% CI 0.874–0.981, p = 0.009) and high-grade tubular atrophy (OR = 0.451, 95% CI 0.208–0.829, p = 0.013) were associated with renal function recovery. During follow up, 25 patients were on end-stage renal disease (ESRD). Kaplan–Meier analysis revealed that renal function recovery after six months and lower probability of ESRD are associated.

Conclusions

In patients with LN and reduced renal function, renal function recovery at six months was associated with use of hydroxychloroquine and inversely related to longer duration of LN and higher grade of tubular atrophy.

Impact of stringent response in proteinuria on long-term renal outcomes in proliferative lupus nephritis

Objectives

Favourable long-term prognosis in proliferative lupus nephritis (LN) is associated with the achievement of complete renal response (CR), which is defined as a urine protein/creatinine ratio (UPCR) of < 0.5. However, it is unclear whether a more stringent cut-off for proteinuria (normal value of proteinuria; UPCR < 0.15) is better than CR. We aimed to evaluate the effect of stringent CR, defined as a UPCR of <0.15, on long-term renal outcomes in proliferative LN.

Methods

We included 87 patients with class III or IV LN who achieved CR at one year after induction therapy. Clinical and laboratory data were compared between the stringent and non-stringent CR groups. Logistic regression analysis was performed to identify factors associated with achievement of stringent CR. Cox analysis was performed to analyse the risk factors for renal flare and development of chronic kidney disease (CKD).

Results

The stringent and non-stringent CR groups included 58 and 29 patients, respectively. The two groups showed no significant baseline differences in terms of the clinical, laboratory and pathological classification. The sustained CR rates during five years were 91.3% and 50.0% ( p = 0.014) in the stringent and non-stringent CR groups, respectively. In Cox analyses, the achievement of stringent CR was associated with a lower risk of five-year renal flare rate (hazard ratio (HR) = 0.161, 95% confidence interval (CI) 0.063–0.411, p < 0.01) and development of CKD (HR = 0.189, 95% CI 0.047–0.752, p = 0.018). Mycophenolate mofetil induction therapy was associated with achievement of stringent CR at a borderline level of significance (HR = 7.268, 95% CI 0.894–59.089, p = 0.064).

Conclusion

Achievement of stringent CR predicted lower risk of renal flare and development of CKD in proliferative LN. These findings suggest that stringent CR is a valuable treatment target in proliferative LN.

Phenformin Induces Caspase-dependent Apoptosis of FaDu Head and Neck Squamous Cell Carcinoma Cells

BACKGROUND/AIM

The present study aimed to investigate the apoptotic effects of phenformin, a therapeutic agent for diabetes, on head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

Cytotoxicity was measured by the MTT and live/dead cell assay. Phenformin-induced apoptotic FaDu cell death and its associated cellular signaling pathways were investigated by hematoxylin and eosin staining, 4',6-diamidino-2-phenylindole staining, caspase-3 activity assay, fluorescence-activated cell sorting analysis, and western blotting.

RESULTS

Phenformin promoted death of and apoptotic processes in FaDu cells, including morphological alterations and nuclear condensation. Furthermore, treatment with phenformin increased caspase-3 activity and apoptotic populations via the caspase cascade through cleavage of capspase-8, -9, and -3 and poly(ADP-ribose) polymerase in FaDu cells. Moreover, phosphorylation levels of mitogen-activated protein kinases, nuclear factor-κB, and AKT were down-regulated in FaDu cells by phenformin.

CONCLUSION

Phenformin induced death of FaDu cells via caspase-dependent extrinsic and intrinsic apoptosis pathways and is a promising novel therapeutic agent for HNSCC.

Anticatabolic Effects of Morin through the Counteraction of Interleukin-1β-Induced Inflammation in Rat Primary Chondrocytes

Morin, a flavonoid isolated from various medicinal herbal plants, has an anti-inflammatory effect. This study aimed to elucidate the anticatabolic effects and cellular mechanism of morin against interleukin-1β (IL-1β) in rat primary chondrocytes. Morin at 10-100 μM did not affect the viability of rat primary chondrocytes. Treatment with morin for 21 days ameliorated the IL-1β-induced decrease in extracellular matrix. Furthermore, treatment with morin attenuated IL-1β-induced proteoglycan loss in the articular cartilage through suppression of catabolic factors, such as matrix metalloproteinases, inflammatory mediators, and pro-inflammatory cytokines. These data indicated that morin exerted anticatabolic effects that can prevent and reduce progressive degeneration of the articular cartilage, and thus may be a potential candidate treatment for osteoarthritis.

A Comparative Study with Biphasic Calcium Phosphate to Deproteinized Bovine Bone in Maxillary Sinus Augmentation: A Prospective Randomized and Controlled Clinical Trial

PURPOSE

The purpose of this study was to evaluate a new graft material, biphasic calcium phosphate, composed of 60% hydroxyapatite and 40% β-Tricalcium phosphate and deproteinized bovine bone mineral, which is established as a predictable graft material for maxillary sinus augmentation.

MATERIALS AND METHODS

Maxillary sinus augmentation was performed with different bone materials. Bone biopsies were performed on tissue harvested from the future implant bed using a trephine bur at 6 months after maxillary sinus augmentation. Resonance frequency analysis was performed immediately and at 6 months after the implant placement. Microcomputed tomography and histomorphometric analysis were performed in all patients.

RESULTS

Fifty-six patients (60 sinuses) were included in the study. At 6 months postoperative, 31 biopsies were performed on tissues harvested from the calcium phosphate, and 29 biopsies on tissues from the bovine bone grafts. There was no implant failure during the 21-month mean follow-up period. The overall implant stability quotient values were higher than 60, and gradually increased for 6 months. Higher new bone volume fraction and new bone surface density were observed in the calcium phosphate group compared with the bovine bone group. In contrast, residual bone graft volume in the bovine bone group was higher than that in the calcium phosphate group. Nevertheless, there was no significant difference between groups in the microcomputed tomography and histomorphometric parameters.

CONCLUSION

Within the study's limitations, both graft materials demonstrated similar biocompatibility and osteoconductivity in the maxillary sinus augmentation.

Clinical and histomorphometric evaluation of decompression followed by enucleation in the treatment of odontogenic keratocyst

Background/purpose

The classification and treatment of odontogenic keratocyst (OKC) are controversial. The objective of this study was to present the efficiency of decompression followed by enucleation by clinical and histomorphometric evaluation for the treatment of OKC.

Materials and methods

Thirty four OKCs of 27 patients who underwent decompression followed by enucleation were included in this study. Clinical and histomorphometric analysis were performed.

Results

The average decreasing rate was 59% in maximum diameter, 66% in the amount of the volume for the average of period of the decompression was 9.8 months. The mean of increasing rate of the thickness of the epithelial lining was 921.16%. There were no recurrences for a mean follow-up period of 5.8 years. The thin and friable cyst wall of the OKC was changed to thickened, hard type.

Conclusion

The decompression was found to be effective and reliable as a treatment of the OKC to decrease the recurrence tendency, even for Gorlin-Goltz syndrome.

Evaluation of abundance of artificial radionuclides in food products in South Korea and sources

Food samples are collected nationwide from January 2016 to February 2017 and their contents of artificial radionuclides are measured to address the growing concerns regarding the radioactive contamination of food products in Korea. Specifically, 900 food samples are collected for this study and their contents of representative artificial radionuclides ¹³⁴Cs, ¹³⁷Cs, ^239,240Pu, and ⁹⁰Sr are analyzed. The analysis shows that the activity concentrations of ¹³⁷Cs in fish range from minimum detectable activity (MDA) to 340 mBq/kg of fresh weight. The concentration factor (CF) determined for ¹³⁷Cs as a measure of its bioavailability is calculated to be ca. 74 and found to be very similar to that (100) recommended by the International Atomic Energy Agency. With an MDA of <0.221 mBq/kg, the results reveal that ^239,240Pu values in fish are below the MDA. The activity concentrations of ¹³⁷Cs and ⁹⁰Sr are lower than the MDA in both shellfish and seaweed, while the activity concentrations of ^239,240Pu in shellfish range from 0.26 to 2.18 mBq/kg, and for seaweed samples range from 2.07 to 3.38 mBq/kg. The atom ratios of ²⁴⁰Pu/²³⁹Pu in shellfish caught at the Korean coast vary from 0.209 to 0.237, with a mean of 0.227. The higher ²⁴⁰Pu/²³⁹Pu atom ratio determined in shellfish is thought to be caused by the plutonium transported from the Pacific Proving Grounds rather than other sources such as the Fukushima nuclear power plant accident. The activity concentrations of ¹³⁷Cs in mushrooms are found to vary from 1.0 to 21.4 Bq/kg, with the highest concentrations observed in the Oak (shiitake) and Sarcodon asparatus. ¹³⁴Cs is detected in three mushroom specimens collected from Jeju Island and about 3-3.6% of ¹³⁷Cs present in the wild mushrooms native to the Jeju Island are introduced as a result of the Fukushima nuclear plant accident. The annual effective doses of ¹³⁷Cs received through consumption of mushrooms and fish are 2.0 × 10^-4 mSv yr^-1 and 3.9 × 10^-5 mSv yr^-1, and those values are negligible compared to the annual effective doses limit of 1 mSv yr^-1.

Collagen sponge and rhBMP-2 improve socket healing in rats treated with zoledronic acid

The aim of the present study was to evaluate the possible use of a commercial absorbed collagen sponge and bone morphogenetic protein (BMP) for the prevention of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in rats. Twenty rats received intraperitoneal injections of 0.1-mg/kg of zoledronic acid three times a week for eight weeks before the extraction of both maxillary first molars after eight weeks. A collagen sponge (experimental group 1) and a collagen sponge with recombinant human BMP-2 (experimental group 2) were applied to the right extraction sockets of ten rats each. The 20 left extraction sockets (control groups 1 and 2) were left unprotected. After eight weeks, all rats were euthanized. Macroscopic analysis, micro-computed tomography (CT) analysis, and histological analysis were performed. There was a significant difference in the bone density between the control and experimental groups on micro-CT analysis. Impaired healing of the extraction sockets, indicating BRONJ, was observed in 80% of control group 1, 90% of control group 2, 30% of experimental group 1, and 20% of experimental group 2. The collagen sponge with/without BMP used for protecting the extraction socket had the potential for a positive effect in reducing the incidence of bisphosphonate-related osteonecrosis of the jaw in rats.

Comparative Study on Early Osseointegration of Implants According to Various Drilling Speeds in the Mandible of Dogs

PURPOSE

This study evaluated the effect of drilling speed on early bone healing in the mandible of dogs.

MATERIAL AND METHODS

Six dogs were selected, and mandibular premolars and molars were extracted. After 2 months, 3 hydroxyapatite-surfaced fixtures were implanted with drilling speeds of 50, 800, and 1200 rpm on the right side first and then on the left side after 2 weeks. Implant stability quotient (ISQ) was measured on insertion, after 2 and 4 weeks.

RESULTS

Based on the ISQ measurement, the 1200-rpm group showed a higher value than the 50-rpm group at 2 weeks and 4 weeks (P < 0.05). New bone formation around the implant was highest for the 800-rpm group at 2 weeks and the 1200-rpm group at 4 weeks. The bone-implant contact of the superior half of the alveolar bone was highest for the 800-rpm group at 2 weeks and the 1200-rpm group at 4 weeks. There was no statistically significant difference.

CONCLUSION

This study suggests that 50, 800, and 1200 rpm are drilling speeds which can expect favorable outcome, yet, higher drilling speed presented overall the best biological responses.

Removal of a fractured needle during inferior alveolar nerve block: two case reports

The inferior alveolar nerve block is the most common method of local anesthesia for intraoral surgery at the posterior mandibular region. However, unexpected complications may occur when administering the local anesthesia. One of these uncommon complications is the fracture of the needle. If the injection needle is broken during the surgery, it should be removed immediately. However, this is one of the most difficult procedures. In this report, we present two cases of needle fracture during the procedure, and its successful removal under general/local anesthesia administration.

Comparative Study on Osseointegration of Implants After Flap and Flapless Surgery in the Mandible of Dogs

PURPOSE

The objective of this study was to compare the implant stability and osseointegration of implants using a flap or flapless technique.

MATERIAL AND METHODS

Mandibular premolars and molars were extracted from both sides in 6 dogs. After 8 weeks, 4 fixtures were implanted using either a flap or flapless technique. Implant stability quotient was measured on insertion and at 2, 4, and 8 weeks later. The animals were killed while the tissues were histologically analyzed.

RESULTS

Implant stability increased for 8 weeks, and no statistically significant differences were observed between the surgical protocols. Bone-implant contact showed 60.27% ± 30.99% for flapless surgery and 59.73% ± 17.12% for flap surgery. And the results of new bone formation area from total area showed 56.07% ± 27.78% for flapless surgery and 57.00% ± 14.66% for flap surgery. There were no statistically significant differences.

CONCLUSION

This study showed no significant difference in implant stability as well as osseointegration regardless of flap or flapless technique.

Licochalcone-E induces caspase-dependent death of human pharyngeal squamous carcinoma cells through the extrinsic and intrinsic apoptotic signaling pathways

The aim of the present study was to investigate licochalcone-E (Lico-E)-induced apoptosis and the associated apoptotic signaling pathway in FaDu cells, a human pharyngeal squamous carcinoma cell line. Treatment with Lico-E exhibited significant cytotoxicity on FaDu cells in a concentration-dependent manner. The IC50 value of Lico-E in FaDu cells was ~50 µM. Treatment with Lico-E increased the number of dead FaDu cells. Furthermore, chromatin condensation, which is associated with apoptotic cell death, was observed in FaDu cells treated with Lico-E for 24 h. By contrast, Lico-E did not produce cytotoxicity or increase the number of dead cells when applied to human normal oral keratinocytes (hNOKs). Furthermore, chromatin condensation was not observed in hNOKs treated with Lico-E. Treatment with Lico-E increased the expression of Fas ligand and the cleaved form of caspase-8 in FaDu cells. Furthermore, treatment with Lico-E increased the expression of pro-apoptotic factors, including apoptosis regulator BAX, Bcl-2-associated agonist of cell death, apoptotic protease-activating factor 1, caspase-9 and tumor suppressor p53, while decreasing the expression of anti-apoptotic factors, including apoptosis regulator Bcl-2 and Bcl-2-like protein 1 in FaDu cells. The expression of cleaved caspases-3 and poly (ADP-ribose) polymerase was significantly upregulated following treatment with Lico-E in FaDu cells, while Lico-E-induced apoptotic FaDu cell death was partially suppressed by treatment with Z-VAD-FMK, a pan caspase inhibitor. Therefore, Lico-E-induced oral cancer (OC) cell-specific apoptosis is mediated by the death receptor-dependent extrinsic and mitochondrial-dependent intrinsic apoptotic signaling pathways. In conclusion, these data suggested that Lico-E exhibits potential chemopreventive effects and warrants further developed as a chemotherapeutic agent against OC.

Coumestrol Counteracts Interleukin-1β-Induced Catabolic Effects by Suppressing Inflammation in Primary Rat Chondrocytes

In the present study, we investigated the anti-catabolic effects of coumestrol, a phytoestrogen derived from herbal plants, against interleukin-1β-induced cartilage degeneration in primary rat chondrocytes and articular cartilage. Coumestrol did not affect the viability of human normal oral keratinocytes and primary rat chondrocytes treated for 24 h and 21 days, respectively. Although coumestrol did not significantly increase the proteoglycan contents in long-term culture, it abolished the interleukin-1β-induced loss of proteoglycans in primary rat chondrocytes and knee articular cartilage. Furthermore, coumestrol suppressed the expression of matrix-degrading enzymes such as matrix metalloproteinase-13, -3, and -1 in primary rat chondrocytes stimulated with interleukin-1β. Moreover, the expression of catabolic factors such as nitric oxide synthase, cyclooxygenase-2, prostaglandin E₂, and inflammatory cytokines in interleukin-1β-stimulated primary rat chondrocytes was suppressed by coumestrol. In summary, these results indicate that coumestrol counteracts the catabolic effects induced by interleukin-1β through the suppression of inflammation. Therefore, based on its biological activity and safety profile, coumestrol could be used as a potential anti-catabolic biomaterial for osteoarthritis.

The effect of decompression as treatment of the cysts in the jaws: retrospective analysis

Objectives

The purpose of this study is to evaluate the treatment efficacy of enucleation after decompression.

Materials and Methods

A total of 17 patients with cystic lesion of the jaw were treated with decompression followed by enucleation. Pre- and postdecompression panoramic radiographs were analyzed.

Results

The mean percentage of reduction after decompression was 64%. The reaction was graded as good (>80%) in five patients (29.4%), moderate (50%-80%) in nine patients (52.9%), and poor (<50%) in three patients (17.6%). The reduction rate of larger cystic lesions was faster than that of smaller lesions. However, the reduction rate was not affected by age. The duration of follow-up ranged from one to eight years. There were no complications, and one case recurred.

Conclusion

Decompression is an effective method for the initial treatment of jaw cysts.

Comparative study of postoperative stability between conventional orthognathic surgery and a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy for skeletal class III correction

Objectives

The purpose of this study is to compare the postoperative stability of conventional orthognathic surgery to a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy (BSSRO).

Materials and Methods

The study included 20 patients who underwent BSSRO for skeletal class III conventional orthognathic surgery and 20 patients who underwent a surgery-first orthognathic approach. Serial lateral cephalograms were analyzed to identify skeletal changes before surgery (T0), immediately after surgery (T1), and after surgery (T2, after 1 year or at debonding).

Results

The amount of relapse of the mandible in the conventional orthognathic surgery group from T1 to T2 was 2.23±0.92 mm (P<0.01) forward movement and −0.87±0.57 mm (non-significant, NS) upward movement on the basis of point B and 2.54±1.37 mm (P<0.01) forward movement and −1.18±0.79 mm (NS) upward movement on the basis of the pogonion (Pog) point. The relapse amount of the mandible in the surgery-first orthognathic approach group from T1 to T2 was 3.49±1.71 mm (P<0.01) forward movement and −1.78±0.81 mm (P<0.01) upward movement on the basis of the point B and 4.11±1.93 mm (P<0.01) forward movement and −2.40±0.98 mm (P<0.01) upward movement on the basis of the Pog.

Conclusion

The greater horizontal and vertical relapse may appear because of counter-clockwise rotation of the mandible in surgery-first orthognathic approach. Therefore, careful planning and skeletal stability should be considered in orthognathic surgery.

Comparative study on the osseointegration of implants in dog mandibles according to the implant surface treatment

OBJECTIVES

This study compared the impact of implant surface treatment on the stability and osseointegration of implants in dog mandibles.

MATERIALS AND METHODS

Six adult dogs received a total of 48 implants that were prepared using four different surface treatments; resorbable blast media (RBM), hydroxyapatite (HA), hydrothermal-treated HA, and sand blasting and acid etching (SLA). Implants were installed, and dogs were separated into 2- and 4-week groups. Implant stability was evaluated via Periotest M, Osstell Mentor, and removal torque analyzers. A histomorphometric analysis was also performed.

RESULTS

The stability evaluation showed that all groups generally had satisfactory values. The histomorphometric evaluation via a light microscope revealed that the HA surface implant group had the highest ratio of new bone formation on the entire fixture. The hydrothermal-treated HA surface implant group showed a high ratio of bone-to-implant contact in the upper half of the implant area.

CONCLUSION

The hydrothermal-treated HA implant improved the bone-to-implant contact ratio on the upper fixture, which increased the implant stability.

Treatment of nevoid basal cell carcinoma syndrome: a case report

Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is characterized by various embryological deformities and carcinoma formation. It is caused by PTCHI gene mutations and is autosomal dominantly inherited. Some of the main symptoms of NBCCS are multiple basal cell carcinomas, multiple keratocystic odontogenic tumors (KCOTs) of the mandible, hyperkeratosis of the palmar and plantar, skeletal deformity, calcification of the falx cerebri, and facial defomity. Recurrent KCOT is the main symptom of NBCCS and is present in approximately 90% of patients. In NBCCS, KCOTs typically occur in multiples. KCOTs can be detected in patients under the age of 10, and new and recurring cysts develop until approximately the age of 30. The postoperation recurrence rate is approximately 60%. This case report presents a 14-year-old female patient with a chief complaint of a cyst found in the maxilla and mandible. The patient was diagnosed with NBCCS, and following treatment of marsupialization and enucleation, the clinical results were satisfactory.

Mini-plate removal in maxillofacial trauma patients during a five-year retrospective study

OBJECTIVES

The purpose of this study was to analyze the incidence of indications for the removal of mini-plates over a five-year period in maxillofacial trauma patients.

MATERIALS AND METHODS

The medical records of 530 patients who underwent treatment with mini-plate fixation after maxillofacial trauma were reviewed for a five-year period (May 2007 to May 2012). Patients were evaluated concerning the number of mini-plates removed, age and gender distributions, time between insertion and removal, indication for removal, and site of removal.

RESULTS

The plates of 120 patients were removed (26 females and 94 males). The removal rate was 22.6%. The most frequent indication for removal was patient demand (81.7%), followed by tooth extraction (7.5%), and pain (3.3%). The most frequent removal site was the mandible (95.0%).

CONCLUSION

The number of mini-plates removed was small, and the most common indication for removal was patient demand. There is no evidence to support a recommendation for the routine removal of titanium mini-plates.

Berberine-induced anticancer activities in FaDu head and neck squamous cell carcinoma cells

In the present study, we investigated berberine‑induced apoptosis and the signaling pathways underlying its activity in FaDu head and neck squamous cell carcinoma cells. Berberine did not affect the viability of primary human normal oral keratinocytes. In contrast, the cytotoxicity of berberine was significantly increased in FaDu cells stimulated with berberine for 24 h. Furthermore, berberine increased nuclear condensation and apoptosis rates in FaDu cells than those in untreated control cells. Berberine also induced the upregulation of apoptotic ligands, such as FasL and TNF-related apoptosis-inducing ligand, and triggered the activation of caspase-8, -7 and -3, and poly(ADP ribose) polymerase, characteristic of death receptor-dependent extrinsic apoptosis. Moreover, berberine activated the mitochondria‑dependent apoptotic signaling pathway by upregulating pro-apoptotic factors, such as Bax, Bad, Apaf-1, and the active form of caspase-9, and downregulating anti-apoptotic factors, such as Bcl-2 and Bcl-xL. In addition, berberine increased the expression of the tumor suppressor p53 in FaDu cells. The pan-caspase inhibitor Z-VAD-fmk suppressed the activation of caspase-3 and prevented cytotoxicity in FaDu cells treated with berberine. Interestingly, berberine suppressed cell migration through downregulation of vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-2, and MMP-9. Moreover, the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and p38, components of the mitogen-activated protein kinase pathway that are associated with the expression of MMP and VEGF, was suppressed in FaDu cells treated with berberine for 24 h. Therefore, these data suggested that berberine exerted anticancer effects in FaDu cells through induction of apoptosis and suppression of migration. Berberine may have potential applications as a chemotherapeutic agent for the management of head and neck squamous carcinoma.

Biochanin-A antagonizes the interleukin-1β-induced catabolic inflammation through the modulation of NFκB cellular signaling in primary rat chondrocytes

Biochanin-A, a phytoestrogen derived from herbal plants, protected from the IL-1β-induced loss of proteoglycans through the suppression of matrix degrading enzymes such as matrix metalloproteinase (MMP)-13, MMP-3, MMP-1, and ADAMTS-5 in primary rat chondrocytes and the knee articular cartilage. It also suppressed the expression of IL-1β-induced catabolic factors such as nitric oxide synthase 2, cyclooxygenase-2, prostaglandin E2, and inflammatory cytokines. Furthermore, biochanin-A suppressed the IL-1β-induced phosphorylation of NFκB, and inhibited its nuclear translocation in primary rat chondrocytes. These results indicate that biochanin-A antagonizes the IL-1β-induced catabolic effects through its anti-inflammatory activity that involves the modulation of NFκB signaling.

Early Bone Formation at a Femur Defect Using CGF and PRF Grafts in Adult Dogs: A Comparative Study

PURPOSE

The purpose of this study was to compare the predictability of new bone formation using an autologous concentrated growth factor (CGF) graft alone and platelet graft alone.

MATERIALS AND METHODS

Four bony defects of 8 mm were formed, and 3.7- × 10-mm implants were placed in the right femur. The platelet-rich fibrin (PRF), CGF, and synthetic bone were grafted to the bone defect area. Enzyme linked immunosorbent assay quantitative analysis and microscopic analysis of the fibrinogen structure were performed.

RESULTS

At 4 weeks, the comparisons of each experimental group showed a significant difference between the CGF group and the synthetic bone graft group. When comparing the CGF and allograft material groups, the allograft group showed significantly more new bone formation. In the case of vascular endothelial growth factor, CGF had 1.5 times more than PRF. CGF showed a fibrinogen structure with a constant diameter.

CONCLUSION

When applied to a clinical case, CGF is predicted to show better results than PRF.

Biological Effects of the Herbal Plant-Derived Phytoestrogen Bavachin in Primary Rat Chondrocytes

The aim of this study was to examine the anabolic and anticatabolic functions of bavachin in primary rat chondrocytes. With bavachin treatment, chondrocytes survived for 21 d without cell proliferation, and the proteoglycan content and extracellular matrix increased. Short-term monolayer culture of chondrocytes showed that gene induction of both aggrecan and collagen type II, major extracellular matrix components, was significantly upregulated by bavachin. The expression and activities of cartilage-degrading enzymes such as matrix metalloproteinases and a disintegrin and metalloproteinase with thrombospondin motifs were inhibited significantly by bavachin, while tissue inhibitors of metalloprotease were significantly upregulated. Bavachin inhibits the expression of inducible nitric oxide synthase, a representative catabolic factor, and downregulated the expression of nitric oxide, cyclooxygenase-2, and prostaglandin E2 in a dose-dependent manner in chondrocytes. Our results suggest that the bavachin has anabolic and potent anticatabolic biological effects on chondrocytes, which may have considerable promise in treating articular cartilage degeneration in the future.

Histomorphometric Analysis of Contaminated Autogenous Tooth Graft Materials After Various Sterilization

PURPOSE

The purpose of this study was to evaluate histomorphometrically contaminated autogenous tooth graft materials, which were resterilized.

MATERIALS AND METHODS

The intentional defects (diameter: 8 mm, depth: 4 mm) were formed around implant fixture on the iliac crest of 6 mongrel dogs. Autogenous tooth graft materials were made by extracted premolars. After the contamination of the tooth materials, graft procedure was performed; no contaminated group (control group), contaminated groups (nonsterilization group [group 1], ethylene oxide [EO] gas group [group 2], and autoclave group [group 3]). The bone-to-implant contact (BIC) and the new bone formation rate (NBFR) were evaluated after sacrifice.

RESULTS

The BIC and NBFR of groups 1 and 3 were significantly lower than the control group after 4 weeks. The BIC and NBRF of group 3 were significantly lower than the control group after 8 weeks. However, the BIC and NBRF of group 2 was not significantly different comparing with the control group after 4 and 8 weeks.

CONCLUSION

Sterilization using EO gas may be more favorable than high-pressure sterilization in cases the reuse of contaminated autogenous tooth graft materials.

Sclerotherapy using 1% sodium tetradecyl sulfate to treat a vascular malformation: a report of two cases

Vascular malformations are the most common congenital and neonatal vascular anomalies in the head and neck region. The demand for simple and esthetic vascular malformation treatments have increased more recently. In this study, two patients that were diagnosed with venous malformations were treated with sodium tetradecyl sulfate as a sclerosing agent. Recurrence was not found one year after the surgery. This article gives a brief case report of sclerotherapy as an effective approach to treat vascular malformations in the oral cavity.

New method to incorporate Type B uncertainty into least-squares procedures in radionuclide metrology

We discuss a new method to incorporate Type B uncertainty into least-squares procedures. The new method is based on an extension of the likelihood function from which a conventional least-squares function is derived. The extended likelihood function is the product of the original likelihood function with additional PDFs (Probability Density Functions) that characterize the Type B uncertainties. The PDFs are considered to describe one's incomplete knowledge on correction factors being called nuisance parameters. We use the extended likelihood function to make point and interval estimations of parameters in the basically same way as the least-squares function used in the conventional least-squares method is derived. Since the nuisance parameters are not of interest and should be prevented from appearing in the final result, we eliminate such nuisance parameters by using the profile likelihood. As an example, we present a case study for a linear regression analysis with a common component of Type B uncertainty. In this example we compare the analysis results obtained from using our procedure with those from conventional methods.

A Comparative Study of Stability After the Installation of 2 Different Surface Types of Implants in the Maxillae of Dogs

PURPOSE

This study was performed to investigate the histologic and histomorphometric findings of 2 different types of implant.

MATERIALS AND METHODS

Resorbable blasting media (RBM) and sandblasted with larger grit and acid etched (SLA) surfaced implants (24 fixtures in each group) were installed in posterior maxilla of dogs. The initial stability was measured using Periotest (Periotest value [PTV]). After 6 or 12 weeks, fixtures with surrounding bone were harvested.

RESULTS

The average initial stability of the SLA group (-1.71 ± 2.9) was higher than that of the RBM group (-1.25 ± 3.21), but there was no significant difference. The mean PTV of the RBM surface was higher than the SLA surface at 12 weeks. The average bone-implant contacts were 67.6% ± 16.0% at 6 weeks and 82.7% ± 8.6% at 12 weeks in the SLA group and 69.9% ± 17.6% at 6 weeks and 78.3% ± 9.2% at 12 weeks in the RBM group.

CONCLUSION

The SLA and resorbable blasting media (RBM) surface implants demonstrated good stabilities and healing processes of the surrounding bone in the posterior maxilla. Therefore, the two domestic implants could provide predictable clinical results.

Osteogenic evaluation of collagen membrane containing drug-loaded polymeric microparticles in a rat calvarial defect model

The aim of this study was to develop a functional collagen membrane that is treated with poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with dexamethasone (DEX) as a bioactive molecule for guided bone regeneration (GBR). The DEX-loaded PLGA microparticles prepared using water-in-oil standard emulsion method were precoated with positively charged polyethylenimine molecules and later immobilized onto the surface of the collagen membrane; the microparticles were physically immobilized using counter charges of positively charged PLGA microparticles and the negatively charged collagen membrane surface. The release profile of DEX over a 4-week immersion study indicated an initial burst release followed by a sustained release. The performance of this system was investigated using rats with calvarial bone defects. The in vivo evaluation of the defects filled with membrane containing DEX-loaded PLGA microparticles indicated enhanced volume and quality of new bone formation compared with defects that were either unfilled or filled with membrane alone. This innovative platform for bioactive molecule delivery more potently induced osteogenesis, which may be exploited in implantable membranes for stem cell therapy or improved in vivo performance. In conclusion, this newly developed collagen membrane treated with drug-loaded PLGA microparticles might be applicable as a promising bone graft substitute for GBR.

A comparative analysis of patients with mesiodenses: a clinical and radiological study

Objectives

A mesiodens appears most commonly as a supernumerary tooth impacted in the anterior maxilla. The purpose of this study is analyze mesiodens clinically.

Materials and Methods

Gender, crown form, direction of impaction, relation to permanent incisors, and chief complaints of patients with extracted mesiodens were analyzed.

Results

Patients were analyzed for motivation to visit the hospital; 85.4% of the patients were referred from other hospitals. Mesiodens was more common in males than in females (3.7:1), and 70.1% of patients had only one mesiodens, while 29.6% had two mesiodenses. Of the mesiodenses, 61.4% were of the aconical form, and the most common direction was upward (62.4%), followed by the normal position (26.0%) and the horizontal position (11.6%). The mesiodenses caused orthodontic problems with the permanent incisors in 46.3% of cases. Mesiodens associated with dentigerous cyst was rarely observed in our patient group.

Conclusion

Mesiodens is more common in males than in females and often affects the permanent incisors. Thus, careful clinical and radiological evaluations of mesiodenses are important.

A Comparative Study of Stability After the Installation of 2 Different Surface Types of Implants in the Maxillae of Dogs

PURPOSE

This study was performed to investigate the histologic and histomorphometric findings of 2 different types of implant.

MATERIALS AND METHODS

Resorbable blasting media (RBM) and sandblasted with larger grit and acid etched (SLA) surfaced implants (24 fixtures in each group) were installed in posterior maxilla of dogs. The initial stability was measured using Periotest (Periotest value [PTV]). After 6 or 12 weeks, fixtures with surrounding bone were harvested.

RESULTS

The average initial stability of the SLA group (-1.71 ± 2.9) was higher than that of the RBM group (-1.25 ± 3.21), but there was no significant difference. The mean PTV of the RBM surface was higher than the SLA surface at 12 weeks. The average bone-implant contacts were 67.6% ± 16.0% at 6 weeks and 82.7% ± 8.6% at 12 weeks in the SLA group and 69.9% ± 17.6% at 6 weeks and 78.3% ± 9.2% at 12 weeks in the RBM group.

CONCLUSION

The SLA and resorbable blasting media (RBM) surface implants demonstrated good stabilities and healing processes of the surrounding bone in the posterior maxilla. Therefore, the two domestic implants could provide predictable clinical results.

Relationship between mandibular condyle and angle fractures and the presence of mandibular third molars

OBJECTIVES

We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures.

MATERIALS AND METHODS

This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured.

RESULTS

Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001).

CONCLUSION

The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures.

Evaluation of bone formation after grafting with deproteinized bovine bone and mineralized allogenic bone

PURPOSE

The purpose of this study was to evaluate the ability of new bone formation of deproteinized bovine bone (Bio-Oss) and mineralized allogenic bone (Tutoplast).

MATERIALS AND METHODS

Sixty rats were divided into control and experimental groups (groups 1 and 2): control group, unfilled control; group 1, Bio-Oss; group 2, Tutoplast, respectively. The animals were killed after 6 and 12 weeks, and newly formed bone was analyzed histomorphometrically.

RESULTS

In the control group, some new bone formed in the rim of the defect area. In the group 1, newly formed bone was thinner than the adjacent normal bone, and Bio-Oss particles were observed. In the group 2, showed a pattern of gradual fusion with adjacent bone, as well as particles in some areas, similar to the Bio-Oss-treated group. In the 12-week groups, the amount of new bone formation was significantly higher in the experimental groups than in the control group, and it was significantly higher in group 2 than in group 1.

CONCLUSION

Although Tutoplast and Bio-Oss graft materials seem to be useful for bone grafts, Tutoplast showed more active new bone formation than Bio-Oss.

Berberine induces FasL-related apoptosis through p38 activation in KB human oral cancer cells

In the present study, we examined the anticancer properties of berberine in KB oral cancer cells with a specific focus on its cellular mechanism. Berberine did not affect the cell viability of the primary human normal oral keratinocytes that were used as a control. However, the viability of KB cells was found to decrease significantly in the presence of berberine in a dose-dependent manner. Furthermore, in KB cells, berberine induced the fragmentation of genomic DNA, changes in cell morphology, and nuclear condensation. In addition, caspase-3 and -7 activation, and an increase in apoptosis were observed. Berberine was also found to upregulate significantly the expression of the death receptor ligand, FasL. In turn, this upregulation triggered the activation of pro-apoptotic factors such as caspase-8, -9 and -3 and poly(ADP-ribose) polymerase (PARP). Furthermore, pro-apoptotic factors such as Bax, Bad and Apaf-1 were also significantly upregulated by berberine. Anti-apoptotic factors such as Bcl-2 and Bcl-xL were downregulated. Z-VAD-FMK, a cell-permeable pan-caspase inhibitor, suppressed the activation of caspase-3 and PARP. These results clearly indicate that berberine-induced cell death of KB oral cancer cells was mediated by both extrinsic death receptor-dependent and intrinsic mitochondrial-dependent apoptotic signaling pathways. In addition, berberine-induced upregulation of FasL was shown to be mediated by the p38 MAPK signaling pathway. We also found that berberine-induced migration suppression was mediated by downregulation of MMP-2 and MMP-9 through phosphorylation of p38 MAPK. In summary, berberine has the potential to be used as a chemotherapeutic agent, with limited side-effects, for the management of oral cancer.

The expression of vascular endothelial growth factor and Syndecan-4 in cartilage from osteoarthritic knees

Previous studies support the important role of vascular endothelial growth factor (VEGF) and syndecan-4 in the pathogenesis of osteoarthritis (OA). Both VEGF and syndecan-4 are expressed by chondrocytes and both are involved in the regulation of matrix metalloproteinase-3, resulting in the activation of aggrecanase II (ADAMTS-5), which is essential in the pathogenesis of OA. However, the relationship between VEGF and syndecan-4 has not been established. As a pilot study, we assayed the expression of VEGF and syndecan-4 in cartilage samples and cultured chondrocytes from osteoarthritic knee joints and analysed the relationship between these two factors. Specimens were collected from 21 female patients (29 knees) who underwent total knee replacement due to severe medial OA of the knee (Kellgren-Lawrence grade 4). Articular cartilage samples, obtained from bone and cartilage excised during surgery, were analysed and used for chondrocyte culture. We found that the levels of expression of VEGF and syndecan-4 mRNA did not differ significantly between medial femoral cartilage with severe degenerative changes and lateral femoral cartilage that appeared grossly normal (p = 0.443 and 0.622, respectively). Likewise, the levels of expression of VEGF and syndecan-4 mRNA were similar in cultured chondrocytes from medial and lateral femoral cartilage. The levels of expression of VEGF and syndecan-4 mRNAs were significantly and positively correlated in cartilage explant (r = 0.601, p = 0.003) but not in cultured chondrocytes. These results suggest that there is a close relationship between VEGF and syndecan-4 in the cartilage of patients with OA. Further studies are needed to determine the exact pathway by which these two factors interact in the pathogenesis of OA.

Comparative Study of the Early Loading of Resorbable Blasting Media and Sandblasting with Large-grit and Acid-etching Surface Implants: A Retrospective Cohort Study

Purpose:

This study compares the prognosis (the survival rate and marginal bone loss) of resorbable blasting media (RBM) surface implants and sandblasting with large-grit and acid-etching (SLA) surface implants in the early loading.

Methods:

This study targeted 123 patients treated by implants installation from January 2008 to March 2010. The loading was initiated in the maxilla within three to four months and in the mandible within one to two months. The types of restoration were single crown and fixed partial prosthesis. Those functioned over one year. The implants were classified by the surface of implants as Group 1: RBM surface (GS III; OSSTEM, Busan, Korea) and, Group 2: SLA surface (Superline; Dentium, Seoul, Korea). The groups were categorized by maxilla and mandible and compared by survival rate, marginal bone loss through clinical records evaluation, and radiographic measurements.

Results:

The marginal bone loss in the maxilla was 0.14±0.34 mm (Group 1) and 0.30±0.37 mm (Group 2), a statistically significant difference (P <0.05). In the mandible those were 0.28±0.54 mm (Group 1) and 0.20±0.33 mm (Group 2), not significant (P >0.05). There was no significant difference of marginal bone loss between maxilla and mandible by groups. During observation there was no implant failure, a survival rate of 100%.

Conclusion:

Both surfaces showed an excellent survival rate, and the marginal bone loss was not substantial.

A Clinical Study of Mandibular Angle Fracture

PURPOSE

To establish management protocol for mandibular angle fracture, we describe pertinent factors including cause, impacted third molar and recent treatment tendency.

METHODS

We examined the records of 62 patients who had unilateral mandibular angle fracture. Sixty patients who had open reduction surgery were examined at postoperative weeks 1, 4, 8, 12, and 28.

RESULTS

Left mandibular angle fracture is frequent in younger males. Presence of the mandibular third molar can increase fracture risk. Because of attached muscle, favorable fractures occurred primarily in the mandibular angle area.

CONCLUSION

Extracting the mandibular third molar can prevent angle fractures, and open reduction with only one plate adaptation is generally the proper treatment method for mandibular angle fracture.

Prognosis of closure of large sinus membrane perforations using pedicled buccal fat pads and a resorbable collagen membrane: case series study

For large membrane perforations that develop during sinus-bone grafting, we performed repairs using a pedicled buccal fat pad and a resorbable collagen membrane simultaneously with the bone graft. This study included eight patients. Postoperative maxillary sinusitis developed in two patients, which we managed with incision and drainage, and antibiotics. Ultimately, six patients received 12 implants, three of which failed (75% success). Implant replacement was performed after the removal of the failed replacement, at which point the prosthetic treatment was considered complete. In all of the six cases that we were able to follow-up with, the sinus-bone graft was healing favorably. We observed that the sinus bone height decreased gradually with time. Based on these case series, we conclude that our procedure of repairing large sinus-membrane perforations with a pedicled buccal fat pad and a collagen membrane is a reliable technique.